Simple definition
The WordPress block editor builds pages from structured content blocks such as text, images, and columns.
Purpose and use
The block editor builds publication content from units such as paragraphs, images, lists or plugin-provided components.
How does it work?
Each block has a type, attributes and structure; its output can be stored with content or generated dynamically.
Example and verification
Before updating a plugin, check a publication using its blocks and compare published output with the editor preview.
Points to watch
An available editor block may depend on an active plugin. Disabling it can change display without necessarily removing stored data.
In short
The editor organizes content; available capabilities and final rendering also depend on the theme, plugins and their versions.